body {
  max-width: 640px;
  min-width: 320px;
  margin: 0 auto !important;
}
img {
  max-width: 100%;
}
ul {
  
}
.banner {
  position: relative;
}
.banner img {
  display: block;
}
.banner .b-btn {
  position: absolute;
  bottom: .2rem;
  left: .2rem;
   width: 21.25%;
}
.zf h3 .zf .h3 {
  margin: 0;
}
